Indicator mechanisms



June 2, 1959 c w s 2,888,832

INDICATOR MECHANISMS Filed Nov. 28, 1955 I'll/III INVENTOR BL C NTERS Patented June 2, 1959 INDICATOR MECHANISMS Berl *C. Winters, Gainesville, Fla, assignor to Sperry Rand Corporation, a corporation of Delaware Application November 28, 1955, Serial No. 549,288

4 Claims. (Cl. 74424.8)

The present invention relates to indicator mechanisms. It is particularly concerned with tuning-indicator devices for use with microwave resonator electron tubes of adjustable frequency.

It is often desirable to provide an indication of the operating frequency of a high frequency electron tube such as a klystron having adjustable means for changing its frequency. It is common practice to vary the frequency of such a tube by changing the spacing between two electron permeable grid elements thereof forming the klystron resonator gap. This is generally effected by supporting one of the grid elements by means including a flexible diaphragm so that the spacing between the grids can be changed for varying the capacitance of the resonator.

Each individual tube of a type as aforedescribed requires a certain resonator gap width at which the tube will operate at its mid-band frequency. Heretofore, it has been required that a tuning-indicator device for such a tube be specially tailored to the individual frequency requirements thereof as tubes, even of the same type and size, may require different width gaps for mid-band frequency operation. However, a specially tailored indi cator device might be considered unduly expensive so that no tuning-indicator device would be included with the tube. If no such indicator device were supplied, a loss in an operators time and a reduction in the life of the tuning diaphragm may be incurred as a result of haphazard hunting for the operating frequency center of the tube.

Therefore, it is an object of the present invention to provide an indicator device which is adjustable to the same reference setting for any predetermined position of an adjustable element for changing the charcteristics of an electrical apparatus.

It is another object to provide a tuning-indicator device for tuning a microwave resonator electron tube and providing an indication of the operating frequency thereof, the indicator device being settable to a mid-point operating position relative to a resonator tuning element for any position of the tuning element required for mid-frequency operation of the electron tube so that such a device can be utilized with any one of a number of tubes.

It is yet a further object of the present invention to provide a tuning-indicator device as aforedescribed which has delicate control, provides a clear visual frequency indication, and is of rugged and inexpensive construction for use with any of a large number of high frequency electron tubes designed to have either the same or different mid-band operating frequencies.

The foregoing and other objects and advantages of the present invention are attained :by providing a sleeve having internal and external threaded regions of the same pitch. The external threaded region of the sleeve is supported by means including one of two relatively adjustable spaced elements whose spacing regulates the frequency of a klystron, for example. A tuner screw having a first threaded portion supported by the internal threaded region of the sleeve for adjustment therein is provided for engagement by a second threaded portion near one end of the screw with the other of said elements. The internal and external threads of the sleeve have the same pitch so that the sleeve can be adjusted relative to the tuner screw without changing the screws position and the spacing between the elements. Locking means are provided between the sleeve and said one element so that the tuner screw can be adjusted relative to the sleeve and said one element for changing the position of the other element. Thus, means are provided for presetting the spacing between the two elements to any distance (which might correspond to that required for tuning a klystron to a mid-band frequency point), the sleeve being adjustable relative to the tuner screw without movement of the latter for providing a predetermined relationship between the sleeve and tuner screw for a mid-band frequency indication regardless of what spacing exists between the two elements for mid-band frequency operation of the klystron.

Referring to the drawings:

Fig. l is a perspective view of a reflex klystron including the novel tuning-indicator device of the present invention;

Fig. 2 is a plan view of the device in Fig. 1;

Fig. 3 is an enlarged sectional view of the tuningindicator device shown in Fig. 1;

Fig. 4 is an enlarged side-elevation view of the tuningindicator device in Fig. 1; and

Fig. 5 is a plan view of the top of the device shown in Fig. 4.

Referring now to the drawings, a conventional reflex klystron tube such as is described in U.S. Patent 2,414,785, dated January 21, 1947, is illustrated in Fig. 1 together with the tuning-indicator device of the present invention. Since the klystron is conventional in the art, no detailed description thereof is deemed necessary.

The frequency of the aforementioned klystron can be regulated in a conventional manner by changing the spacing between two relatively movable parts such as grid elements 11 and 12 defining the resonator gap of klystron resonator 13. An increase in spacing between grids 11 and 12 lowers the capacitance of resonator 13 and raises its resonant frequency and, thus, the frequency of the klystron. A decrease in spacing between grids 11 and 12 has the opposite effect of lowering the klystron frequency.

The grid 12 is supported in an upper wall of the resonator 13. The grid 11 is supported by the end of a reentrant portion 14 of the resonator 13. The portion 14 is supported within the interior of resonator 13 by a flexible diaphragm 16 so that the relative spacing between the grids 11 and 12 is readily adjustable for klystron tuning.

A first flange element 17 is affixed to the upper [half of the klystron tube and the upper wall of the resonator 13. A second flange element 18 is aflixed to a lower half of the klystron tube attached to the re-entrant portion 14 of resonator 13. A first pair of screws 21-22 and a further screw 23 are angularly spaced in a circle about the klystron at degree intervals for holding and spacing the flanges 17 and 18 with respect to each other. The pair of screws 2122 are threaded into apertures in the upper flange 17 and provided with pivot ends such as 24 in Fig. 1 for engaging appropriate recesses in flange 18. Springs 2628 are provided for biasing the flanges 17 and 18 together.

The screw 23 comprises part of the tuning-indicator device of the present invention and has a first threaded region 29 engaging a correspondingly threaded aperture through flange 18. A second threaded region 31 of screw 23 has a larger pitch than the first threaded region 29,

3 screw 23 passing through a flange 17 and provided with a slot 32 at its end for adjusting purposes.

A tubular member such as sleeve 33 supports screw 23 within the flange 17, sleeve 33 being internally threaded at 34 so as to be in engagement with the threads along region 31 of the screw 23. An external region 36 of sleeve 33 is also provided with threads of the same pitch as the threads along the internal region of the sleeve.

The sleeve 33 and screw 23 fit through an aperture or opening 37 in flange 17 of slightly larger diameter than that of sleeve 33. First and second adjustable threaded means such as a pair of nuts 38 and 39 are disposed on opposite sides of the upper flange 17 and threaded upon region 36 of the sleeve 33 for holding the sleeve 33 rigid relative to the flange 17. A lock washer 41 is provided between an upper portion of the flange 17 and a lower portion of the nut 38.

The upper end of the sleeve 33 is provided with a metallic cylinder 42 aflixed thereto having an L-shaped slot 43 therein. A screw 44 is provided as shown in Fig. 4 for tightening the cylinder 42 upon the tuner screw 23 when desired for holding screw 23 in a fixed position relative to cylinder '42 and sleeve 33 so that when sleeve 33 is fixed by nuts 3839 relative to flange 17, there can be no change in the relative spacing between the flanges 1718.

The tuner screw 23 is provided with a plurality of spaced annular graduations or indicator markings 46 thereon for indicating the axial relation between the screw 23 and the top of cylinder 42. A marking 46' of greater width than the other markings 46 comprises a central reference mark for screw 23. An axial slot 47 coated with black paint is provided for indicating the angular position of the screw 23 relative to an upper face of the cylinder 42. The aforementioned upper face of the cylinder 42 is provided with a plurality of equally spaced radial indicating lines 48, shown in Fig.

'5, so that the angular position of slot 47 relative to cylinder 42 is readily determinable. When the upper face of cylinder 42 is aligned with the indicator marking 46' on screw 23, the axial marking 47 should be aligned with the axial portion of the L-shaped slot 43 as shown in Fig. 4, for example.

A stop member 49 is provided along the threaded region 29 of screw 23 between flanges 17 and 18. Memher 49 should be adapted to abut against the lower end of the internal threads 34 of sleeve 33 for one limit of adjustment in one direction of the screw 23 and against the upper face of flange 13 for the other limit of adjustment of screw 23 in an opposite direction. The distance between stop member 49 and the lower end of screw 23 along with the pitch of the threads along the regions 29 and 31 of screw 23 should be properly chosen so that when flange 18 is centered between member 49 and the lower end of screw 23 and the upper face of cylinder 42 is aligned with the center frequency marking 46' on screw 23, the same number of turns in one direction of screw 23 will cause stop member 49 to abut flange 18 as will cause the stop member 49 to abut the lower end of the internal threads 34 of sleeve 33 when the screw 23 is turned in the opposite direction.

In order to utilize the tuning-indicator device of the present invention, the exact relative position between flanges 17 and 18 must first be found for obtaining a resonator gap width corresponding to a mid-band frequency for the klystron tube. This is done initially, after ensuring that flange 18 is centered between the stop member 49 and the lower end of screw 23, by loosening nuts 38 and 39 and lock nuts 51-452 provided with screw elements 2122, respectively. Next, the screw elements 2122 are adjusted and nuts 38 39 properly positioned until the spacing between grids 11 and 12 causes the klystron to be operated at a midband frequency, it being insured that the flanges 17 and 18 are in parallelism at this time. Then, the lock nuts 4 51 and 52 are tightened to prevent further movement of screws 21 22. A conventional frequency meter, not shown, may be employed in conjunction with the klystron for determining the frequency at which it is 0perated.

Next, the sleeve 33 is adjusted with screw 44 loose so as not to lock cylinder 42 to screw 23 and nut 38 loose so as not to lock the sleeve 33 against adjustment within nuts 3839. During this adjustment means, not shown, are provided for holding nuts 3839 and screw 23 against rotation, sleeve 33 being rotated and adjusted within nuts 3839 and along screw 23 until the upper end of cylinder 42 is aligned with the center frequency marker 46' provided along screw 23 and the axial marker 47 along screw 23 aligned with the axial portion of L-shaped slot 43. This may be done without rotating nuts 3839 or screw 23 since the internally threaded region of sleeve 33 engaging screw 23 is of the same pitch as the externally threaded region of sleeve 33 engaging nuts 38-39 so that sleeve 33 will freely rotate and axially move relative to screw 23 and the nuts 38- 39. Since the screw 23 is not rotated during the foregoing procedure, the spacing between flanges 17-18 is not changed and the klystron remains tuned to its midband frequency.

After the procedure mentioned in the preceding paragraph is completed, the upper nut 33 is locked into position against the lock washer 41 and flange 17 so that the sleeve 33 is held rigid relative to the flange 17. Thus, it can readily be seen that the upper face of cylinder 42 can be aligned with the mid-band frequency marker 46' on screw 23 for any position of the flanges 17 and 18 with respect to each other. The view of the tuningindicator device in Fig. 4 shows the indicator at the midposition. Tuning of the resonator above or below the aforementioned mid-band frequency is readily accomplished by means of a screw driver which can be inserted into a slot 32 at the top of the screw element 23 for turning thereof provided screw 44 is loose. Rotation of screw 23 causes the spacing between flanges 1718 to change because of the diflerential action of the differentially pitched threads along regions 29 and 31 of screw'23. The threads along regions 29 and 31 might be of the same pitch but in opposite directions, if desired, and relative movement between flanges 1718 could still be effected.

The upper face of the cylinder 42 is provided with radial calibrations 48 shown in Fig. 5 so that one can readily obtain a reading of the angular degree of displacement of screw 23 relative to cylinder 42 from a mid-band position. This may be utilized for providing a fine indication of frequency. The horizontal annular calibrations 46 along the upper portion of the screw 23 may be employed to provide a rough indication of the frequency. A frequency chart should be supplied with each tube having a tuner-indicator device as aforedescribed so that the klystron frequency can be determined from the tuning-indicator markings 46 and 48 as aforedescribed.

Although the tuning-indicator device as aforedescribed has been utilized to great advantage with high frequency klystron tubes as described above, it should be apparent that similar advantages would obtain by utilizing such a device with other electrical apparatus. For example, anytime an axially movable element is employed for changing the characteristics of electrical apparatus, an indicator device as aforedescribed may be combined therewith for providing an indication of the change from any predetermined position of the movable element whereat the electrical apparatus will function so as to have some predetermined electrical characteristic.

Since many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter 2,sss,ss2

contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A device for adjusting the operating characteristics of electrical apparatus by changing the spacing between two relatively movable parts of said apparatus, comprising a first element for conection to one of said parts, a second element for connection to the other of said parts, an aperture through said first element, a tubular member passing through said aperture toward said second element, said tubular member having an externally threaded region and an internally threaded region therealong, said threaded regions having the same pitch, first and second adjustable threaded means disposed along said externally threaded region on opposite sides of said first element for supporting said tubular member relative to said first element, a rod-like member passing through said tubular member, said rod-like member having a threaded region engaging the internally threaded region of said tubular member for adjustment therein, said rod-like member being connected to said second element for changing the spacing between said first and second elements in response to rotation of said rod-like member, said tubular member being adjustable within said first and second threaded means for providing a predetermined relationship between said tubular member and said rodlike member without changing the spacing between said first and second elements.

2. A device as set forth in claim 1, wherein said second element includes a further threaded means of different pitch from said externally and internally threaded regions of said tubular member, a further region along said rod-like member being in threaded engagement with said further threaded means to thereby provide the connection between said rod-like member and said second element.

3. A device as set forth in claim 2, further including a stop member located along said rod-like member intermediate said second element and an end of said tubular member, said stop member being at a center position between said second element and tubular member for the relative position between said rod like and tubular members at which said predetermined relationship therebetween is attained.

4. A device for tuning a microwave klystron tube having a cavity resonator whose frequency is adjustable over a wide frequency band in response to a change in spacing between two relatively movable parts of said resonator, comprising first and second flange elements that are adapted to be fixed to one and the other parts of said resonator, respectively, an opening in said first flange element, a threaded aperture in said second flange element in alignment with said opening, a tubular member passing through the opening in said first flange element and extending in the direction of said second flange element, said tubular member having internally and externally threaded regions of the same pitch, the pitch of the threaded aperture in said second flange element being different from the pitch of the internally and externally threaded regions of said tubular member, first and second threaded means disposed on opposite sides of said first flange element for engaging the externally threaded region of said tubular member to support said tubular member for adjustment relative to said first flange element, and a screw passing through said tubular member and the threaded aperture in said second flange element, said screw having a first threaded region engaging said internally threaded region of said tubular member for adjustment therein, said screw having a second threaded region engaging the threaded aperture in said second flange element for adjustment of the spacing between said first and second flange elements in response to rotation of said screw within said tubular member, said tubular member being adjustable within said first and second threaded means for providing a predetermined relationship between said tubular member and said tuning screw without changing the spacing between said flange elements.

References Cited in the file of this patent UNITED STATES PATENTS 2,414,785 Harrison et al. Ian. 21, 1947 2,450,893 Hansen et al. Oct. 12, 1948 2,497,564 Sorg Feb. 14, 1950 2,501,303 Barford Mar. 21, 1950 2,508,141 Broadway et al. May 16, 1950 2,533,912 Bels Dec. 12, 1950 2,686,890 Davis Aug. 17, 1954 FOREIGN PATENTS 578,840 Great Britain July 15, 1946 

